An electric vehicle is provided with a DC power source, an inverter, and an AC motor for traveling. The inverter converts power (DC power) from the DC power source to AC power for driving the AC motor. A current sensor for measuring current flowing between the inverter and the AC motor is provided to cause an output of the AC motor to follow a target output. Three-phase alternating current has its phases shifted by 120 degrees from each other. Due to this, measurement of current values of two phases allows a current value of a remaining one phase to be estimated. Meanwhile, an electric vehicle provided with a current sensor for each of three phases to obtain accurate current values is described in Japanese Patent Application. Publication No. 2015-192582. The electric vehicle of Japanese Patent Application Publication No. 2015-192582 detects an abnormality of its current sensors from a sum of the current values of the three phases.
Further, Japanese Patent Application Publication No. 2017-028966 describes a device that is provided with current sensors for two phases of three-phase alternating current, and diagnoses an abnormality of the current sensors based on measurement values obtained from the respective current sensors for the two phases. The diagnostic device of Japanese Patent Application Publication No. 2017-028966 specifies an AC peak value for each of the two phases. It determines that an abnormality is occurring in one of the current sensors when a deviation of the peak values of the two phases is greater than a threshold.